1. Field of the Invention
The present invention relates to a collapsible seat device by which a framework composing a seat device such as a baby buggy, a wheelchair and a buggy of the aged can be easily developed and collapsed.
2. Related Art
FIG. 13 is an overall arrangement view of a collapsible baby buggy which is one of the conventional collapsible seat devices
In FIG. 13, there are provided a front leg 81 and a rear leg 82, both upper end portions of which are rotatably connected with an armrest member 83 by means of a hinge 84. At a lower end portion of the front leg 81, there is provided a front wheel 85. At a lower end portion of the rear leg 82, there is provided a rear wheel 86.
At a substantial center of the rear leg 82 with respect to the longitudinal direction, there is provided a rotary member 87, which is rotatably connected with the rear leg 82 by means of a hinge 88. This rotary member 87 is extended upward from the hinge 88 along the rear leg 82. Further, this rotary member 87 is curved in such a manner that it protrudes upward to the rear portion of the rear leg 82. A push rod 89 is rotatably connected with a protruding portion 87b of the rotary member 87 by means of a hinge 90.
This push rod 89 is rotatably connected with a rear end portion of the armrest member 83 by means of a hinge 91. Therefore, the rotation of the push rod 89 is restricted under the condition that the front leg 81 and the rear leg 82 are open.
A front end portion of the connecting member 92 is rotatably connected with a middle portion of the front leg 81 by means of a hinge 93. A rear end portion of the connecting member 92 is rotatably connected with the rotary member 87 by means of the hinge 90 described before. Accordingly, an angle formed between the front leg 81 and the rear leg 82 is restricted to be a predetermined value.
In an upper portion of the protruding portion 87b of the rotary member 87, there is provided an opening and closing lock 94 which is moved upward and downward along the push rod 89. When a step portion 94a formed at the lower end of this opening and closing lock 94 is engaged with a step portion 87a formed at the upper end of the rotary member 87, the rotary member 87 can be put into a lock condition.
However, the following problems may be encountered in the conventional collapsible baby buggy described above. When the conventional baby buggy is collapsed as shown in FIG. 13(B), it is difficult for the baby buggy to be made into a compact condition. Although not shown in FIG. 13, in order to perform various functions, most of baby buggies are equipped with a reclining seat back portion and a sunshade. Therefore, it is difficult to make the baby buggies put in a compact condition when they are collapsed. Especially when the baby buggy has a shopping basket or a baby basket which is detachably attached to it, the baby buggy tends to be bulky even after it has been collapsed. In view of the above circumstances, there is a demand for a framework by which the baby buggy can be made compact after it has been collapsed.
Not only a collapsible baby buggy but also other seat devices such as a wheelchair, an infant chair and a buggy of the aged are required to be compact after they have been collapsed.